Typescript does not work with defaults

[jantimon]

TypeScript Version: 2.2.1 / nightly (2.2.0-dev.201xxxxx)
Try it yourself using this Playground Link

Code

    function fancyMethod({ option1 = true }: { option1?: boolean } = {}) {
        console.log(option1);
    }
    
    fancyMethod("abc");
    fancyMethod(false);
    fancyMethod(42);

Expected behavior:

Typescript will let me know that "abc" or false or 42 are not of type { option1?: boolean }.

Actual behavior:

No type error is shown

[ikatyang]

Possible duplicate of #7485, and it was said that was fixed by #16047.

See #16247 (comment)

But it seems primitive types are still not considered a weak type.

EDIT: should fixed in #16343

[jantimon]

Thanks for your feedback :)

Is there any way to find out the current playground version number?
Is there a nightly playground?

[ikatyang]

You can see the version in the console.

But I think it will be v2.3.3+ based on #16131 (comment), so weird.

And selectable playground version is tracked by #15662.

EDIT: fix typo